THE WOODLANDS, Texas — Scientists from 37 countries are discussing the latest and greatest planetary science discoveries this week, but a few folks are notably absent: high-ranking NASA officials.

Instead of briefing the 1,750 attendees of the 44th Lunar and Planetary Science Conference here in person, two senior NASA officials beamed in via Skype Monday to detail some of the finer points of the space agency's budget and goals for the coming years.

"It's a pleasure to be coming to you from D.C., though I'd much rather be in Houston with all of you," said John Grunsfeld, NASA's associate administrator for science missions at the agency's headquarters in Washington.

Neither Grunsfeld nor Jim Green, director of NASA's planetary sciences division, is attending the conference. The two space agency officials explained that in light of the new budgetary constraints known as the "sequester," they decided to stay at NASA headquarters so funds for their travel could be used by active researchers.

Indeed, travel budgets for civil servants were one of the first things to be cut after the sequester came into effect on March 1, other NASA officials have said.